Saltwater fish are susceptible to a multitude of ailments in the home aquarium.  Not only are they subjected to tremendous stress while being transported but they are in close quarters with many other stressed fish while being held at wholesalers and your local fish store.  By the time they get to your tank it is no wonder that they are often a bit sick and it isn’t always obvious to spot.

Some of the things you should look for however when purchasing a new fish are:

1. Behavior- How is it swimming? Is it interacting with the other fish?

Take some time to watch the fish you have your eye on.  If it is swimming erratically or off-balance you need to look for another fish.  Is it scratching its body against the rocks or substrate?  If so you don’t want it either. Is it hidden in a corner and not active?  All of these are cause for concern and you should refrain from purchasing.  Trust me I know how tempting it is. You will ignore me much as I have and do it anyway.  I just did and I regret it wholeheartedly.

2. Condition- How does the fish look?

Visually inspect the fish for lesions, imperfections, spots, dots, bumps you get the idea.  Are the fins torn?  Maybe you think it is just from another fish picking on it, or perhaps it has parasites that are eating away at its tissue.  All that can come of us purchasing sick fish is that our local stores will keep stocking them.  After all it guarantees we will return to replace that fish once it dies.  Be aware, be responsible, and be careful.

3. Health- will it eat?

Don’t be afraid to ask your store owner if they will throw in some food.  Odds are if they give you some excuse they are either not feeding their fish, the fish is knowingly not eating or they aren’t willing to find out if the fish is healthy for you.  All of these are reasons to take your business elsewhere.

Can fish heal?  Of course they can, but the majority of the time a fish that is already in distress isn’t going to recover after you move it again causing even more stress.  Also, unless your tank is perfect you are likely not giving the fish a better chance at survival.  Above all you don’t want to risk the other tank inhabitants that you already have successfully living in your tank.  Think of it like placing a child with the flu in a classroom and hoping that none of the other kids will get sick.  Trust me, they will.

Ask your store how the fish are treated.  The distributor they purchase from should treat the fish for diseases and parasites and many stores will treat the fish again once they arrive at the store.  This is done in a bath of medications which will eradicate many of the parasites and diseases commonly seen in the hobby.  Now as you know I don’t like the idea of adding medications to your tank, but it is vital to avoid transferring sick fish to your show tank.

Some of the things you can do before moving your fish to your tank is to have a quarantine tank.  Give the fish some time to acclimate outside or your main tank where you can monitor his progress, catch him if necessary for treatment or treat the quarantine tank instead of your main tank.  If you haven’t already heard many treatments such as copper are lethal to corals so don’t get to crazy with chemicals.  I personally like to stick with a fresh water dip which doesn’t take care of everything but it doesn’t wipe out quite a few parasites.

If your fish gets sick let your local fish store know they had a sick fish.  They likely won’t do anything about it, but if one fish is sick in their system it is very likely that others are too especially if we are talking parasites.

You know what a healthy fish looks like now so please take your time before you make a purchase and treat the fish before you plop it into your tank.  The least you have to worry about is one fish not making it.  The most is the need to basically dismantle your tank because you ended up with isopods.

If you guys know how to stop them please post a reply for all to read.